The present invention relates to footwear and more particularly to a footwear construction and a method for making the same.
In the footwear industry, there is an ongoing effort to produce footwear that provides stability and support while maintaining a high level of comfort. These needs are particularly acute in the design of high performance footwear, such as hiking, mountaineering, multisport and rugged outdoor walking footwear, where one of the primary goals is to reduce fatigue. To minimize the effects of travel over jagged, rugged or uneven surfaces it is important to provide high performance footwear with both torsional stability (e.g. resistance to twisting forces) and longitudinal stability (e.g. resistance to linear forces).
Conventionally, the interests of stability and comfort have been competing interests. Efforts to improve stability and support typically result in a reduction in comfort. For example, a common technique for improving comfort is too increase the amount of cushioning material in the sole assembly, such as by manufacturing the midsole from a softer, more resilient material. While this increases comfort, it reduces the stability and comfort of the article of footwear. Likewise, a common technique for increasing stability and support is to provide a rigid insole or a rigid midsole. As both of these components lie close beneath the foot, a rigid insole or midsole typically provides very limited cushioning and therefore results in reduced comfort. Another technique for increasing stability is to sandwich a rigid arch support or heel support between the midsole and the insole. Again, these components lie just below the wearer""s foot and provide little room for cushioning. As a result, there remains a long felt and unmet need for a footwear construction that provides the desired level of cushioning, stability and support.
The aforementioned problems are overcome by the present invention which provides an extended structural component, or flexplate, molded in situ within the midsole. The flexplate is preferably disposed centrally within the midsole where it is entrapped within the relatively soft material of the midsole. The flexplate is rigid and extends substantially along the entire length and width of the midsole to provide full support for the wearer""s foot. In a preferred embodiment, the flexplate defines a plurality of openings that permit the midsole material to flow about and thoroughly entrap the flexplate. Further, in a preferred embodiment, the heel portion of the flexplate is cupped to, among other things, aid in centering the wearer""s foot.
In another preferred embodiment, the present invention includes a rear stabilizer that provides even further enhanced stability in the heel region. The rear stabilizer is preferably molded in place about the heel portion of the midsole. The rear stabilizer is molded from a relatively rigid polymer, typically from the same family of polymers as the remainder of the midsole.
The sole of the present invention is preferably manufactured using the general steps of (a) providing a rigid flexplate, (b) providing a mold with flexplate locating pins, (c) suspending the flexplate within the mold between the locating pins, (d) molding the midsole about the flexplate, (e) molding the rear stabilizer about the midsole, (f) attaching an outsole to the midsole, and (g) attaching the upper to the midsole/outsole combination.
The present invention further includes a dual-density collar disposed about the ankle portion of the upper. The collar includes a first relatively soft polymer that permits the collar to be stitched directly to the upper and a second relatively stiff polymer that provides the collar with the desired level of rigidity. The two layers are molded together to form a single, integral unit. In the preferred embodiment, the collar is anchored to the sole and provides a mounting location for a lacing hook. As a result, the lacing pressure on the lacing hook is distributed over a large portion of the footwear, including the sole.
The collar of the present invention is preferably manufactured using the general steps of (a) providing a mold having distinct cover molds, (b) molding the first layer of the collar in a first shot of material having a first rigidity, (c) replacing the first cover mold with a second cover mold, and (d) molding the second layer of the collar in a second shot of material having a second rigidity, typically from the same family of polymers as the material of the first shot.
The present invention provides a unique footwear construction having a heretofore unachieved combination of comfort, stability and support. The flexplate provides torsional and linear stability over the entire foot. The rear stabilizer provides enhanced stability in the heel region where torsional forces can be particularly damaging. The cupped heel region of the flexplate helps to center the wearer""s heel. The collar provides stability and support to the heel and ankle regions of the upper while simultaneously distributing lacing pressure over the upper and into the sole. Accordingly, the collar helps to anchor the wearer""s foot to the sole to take full advantage of the stability and support provided by the flexplate.
These and other objects, advantages, and features of the invention will be readily understood and appreciated by reference to the detailed description of the preferred embodiment and the drawings.